Knife-coating apparatus



Jan. 28, 1941.

y F. w. ADAMS KNIFE-COATING APPARATUS Filed Sept. 28, 1938 2 Sheets-Sheet 1 mm Whg x..

INVENTOR 4flow. /4/ ADA/us.

BY il! ATTORNEY Jan. 28, i941.. F w ADAMS 2,229,831 l KNIFE-COMING APPARATUS Filed Sept. 28, 1938 2 Sheets-Sheet 2 lNvENToR 'Ho o VK AOA/11S. am gm- M Q l ATTORNE Patented Jan. 28, 1941 UNITED STATES PATENT OFFICE 2,229,331v xNmE-coarrNG APPARATUS of Delaware Application September 28, 1938, Serial No. 232,035

19Claims.

This invention relates to an improvement in knife-coating apparatus, and in particular to knife coating apparatus for applying a coating of a layer of asphalt or other appropriate material on brous sheet material, either as continuous sheets or single sheets, formed by a process involving felting of ligno-cellulose iibers from a water suspension of fibers and then partially permeated or saturated with an asphaltic substance or with some other substance or compound having approximately the same general characteristics.

The fibrous sheet material or insulating board material which is to be surface-coated, as it is a felted fiber product manufactured from relatively coarse bers derived from vegetative sources, y contains a large proportion of air space provided by the relatively loose fibrous structure thereof, which characteristic imparts to the finished surface-coated fibrous sheet an appreciable resiliency and relatively high insulating value. To maintain this resiliency and relatively high insulating value, the application of the saturant is preferably such that the bers themselves are not saturated but rather that a large part of, or substantially all of the interior interstices or voids within the sheet are partially filled with a saturating material. The thermal insulating units or flooring for which my apparatus is adapted to knife coat is preferably saturated in accordance with the disclosure as set forth in the copending application of George E. Swenson, Serial No. 180,772, led December 20, 1937, for Building material.

The layer of the material to be applied to the impregnated sheet material with the knife-coating apparatus should preferably be about 11g thick and should be of a material which in general has physical characteristics of the nature of asphalt, as for example, having the characteristic of being water-proof, water insoluble, ductile or rubbery, potentially adhesive, etc. The insulating sheet, as above described, either saturated or saturated and coated, as it has been described, will form a quite rigid product having, due to the nature of its construction and composition, a limited amount of resilience, and it is waterproof and also aperiodic.

It is, therefore, a principal object of my invention to provide a novel apparatus for knifecoating a thin coating of asphalt, bitumastic, or bitustatic compound which will be described later with respect to the operation of the apparatus to felted fiber insulating board prepared as described above. or for knife-coating with any suitable compound. i

A ,feature of my invention is to provide anovel knife-coating apparatus which may be adjusted as the units or sheet material are conveyed 5 through the apparatus thus making it unnecessary to stop the machine for making the adjustments for the thickness of the sheet or of the coating to be applied.

Another feature of my invention is to simullo taneously clean the thermal insulating unit or sheet material and to knife-coat it as it is conveyed through the apparatus.

With this object and other objects and features in view, the invention resides inlthe novel details 15 of construction and combination of parts as will be disclosed more fully hereinafter and particularly pointed out in the claims.

Referring to the accompanying drawings which form part `of this specification and in which like 20 numerals designate like parts in all the views- In the drawings:

Figure 1 is a plan view of a machine incorporating the features of the invention;

Figure 2 is a,side elevation of the apparatus 25 shown in Figure 1;

Figure 3 is a plan view of the novel knifecoating guides mounted for vertical adjustment;

Figure 4 is a side elevation of the knife-coating guides and the means for adjusting the knife- 30 coating means;

Figure 5 is a sectional view along line 5-5 of Figure 4 illustrating the adjustment for the knifecoating means; and,

Figure 6 is a sectional view illustrating the 35` means for adjusting the knife-coating means.

Without referring by number to the parts and elements involved, a brief description of the units making up the machine will be given to show the general arrangement of parts and their coopera- 40 tion with each other. The knife-coating apparatus comprises a supporting structure for the various units and has at each end operating stations. Thel thermal insulating units are fed from one n .of the operating stations through brushing means for cleaning the surface of the thermal insulating units. As the'thermal insulating units are fed through the brushing means they are picked up by a conveyor in the form of a roller feed mechanism and fed under the pressure means for maintaining the ,surface of the units level. The thermal insulatingunits or sheet material, which are to be coated as they are fed underneath the pressure means by the conveyor means are lmifecoated by the knife-coating means. After these units have been knife-coated they are transferred from the knife-coating means by another similar conveyor or other apparatus to the other operator station where the units are then piled for another coating operation which in this instance is preferably a coating of shellac. With the novel knife-coating apparatus about to be described, it is possible for the operator to adjust the thickf ness of the coating applied to the thermal insulating unit or sheet material as it passes through the knife-coating apparatus. It is therefore possible with this apparatus to provide a uniform coating of material on the material to be coated at all times. The brush or cleaning means for the thermal insulating units, together with the conveying means are suitably drivenI so that as the sheet material or thermal insulating units are i cleaned, they are knife-coated.

In the drawings, Figures 1 and 2 show certain essential parts of the frame structure on which the various units of the knife-coating apparatus are rigidly supported. The knife-coating apparatus I9 of my invention, principally comprises a supporting frame I I on which there are mounted a conveying means I2 and a cleaning mechanism I3. 'Ihe cleaning roll brush mechanism I3 or means for cleaning the sheet material is mounted ahead of the conveying means I2. The feeding mechanism I2 serves to convey the thermal insulating unit or sheet material from the cleaning roll mechanism I3 to a knife-coating mechanism or means for knife-coating the sheet material I4. Another conveying means I2, adjacent the knife-coating means, serves to transport the sheet material or thermal insulating units from the knife-coating means. At each end of the knife-coating apparatus are operatorstations I5 and I6, respectively, the inlet and outlet ends of the machine.

As an operator takes th`e sheet material or thermal insulating units from the operator station I5, another operator feeds the units from the station I5, and the units or sheet material pass over rollers I1 to a brush I8, preferably of wire, which is a part of the means for cleaning the sheet material. The wire brush I8 is made up in cylinder form and preferably extends the width of the machine which corresponds to the width of the sheet material to be brushed and cleaned. The brush I8 is mounted on a shaft I9 which is journaled and adjustably mounted in bearing 20 for vertical movement. Hand Wheels 2I serve to adjust the wire brush vertically with respect to the sheet material through adjusting screws 22 adjustably secured to the bearings 20.

'I'he brushing means is suitably rotated to clean the surface of the thermal insulating unit or sheet material by having a sprocket 23 secured to the shaft I9. The sprocket 23 is in turn driven from a sprocket 24 secured to a shaft of a motor 26 and is driven through a chain 25.

The novel conveying means I2 of my invention preferably comprises a roller feed mechanism, having an upper and lower feed roll 21 and 28, respectively. 'I'he upper and lower feed rolls 21 and 28 are mounted on upper and lower shafts 29 and 30 respectively. The upper shaft 29 is journaled in adjustable bearings 3l, while the lower shaft 30 is journaled to the frame of my knife-coating apparatus. The adjustable bearings 3I are vertically mounted on guide 32. Hand Wheels 33 serve to adjust the upper feed roll 21 through adjusting screws 34 in threaded engagement with the bearings 3|, the adjusting screws roller feed mechanism I2.

34 being in threaded engagement with supports As a means for conveying a sheet cf material through the knife-coating apparatus I4, I provide the roller feed mechanism I2 adjacent the inlet station and the roller feed mechanism I2'adjacent the outlet station of the apparatus; and, as they are similar, like reference characterswill indicate similar constructions.- A supporting structure 35 serves to mount the adjusting means for the brushing apparatus I3 and also for the first Similarly, a support 38 serves to support the upper roll 21 of the roller feed mechanism I2 adjacent the outlet station I6. A cross member 38 serves as the upper connection for the vertical guides 32 of the adjusting mechanism for the brush I8 and for the upper roll 21.

A platen 39 which is substantially level serves to support the sheet material or insulating unit as it is conveyed through the knife-coating apparatus in order that a uniform coating will be applied to the surface of the sheet material. The platen 39 is supported at one end adjacent the roller feed mechanism I2 by a shaft or transverse support 4U. The opposite end of the platen 39 is secured to the supporting structure II of the knife-coating apparatus in any suitable manner. Knife-coating guides 4I are suitably mounted on the transverse shaft 40 in order that the knife-coatingguides may be vertically adjusted. The knife-coating guides 4I not only serve to guide the sheet material or unit through the knife-coating apparatus but also serves to protect the edges of the sheet material and unit from being coated with the material with which the upper surface of the sheet material and units are being coated. The side sheets or knife-coating guides 4I are supported by vertical supports 42. The supports 42 are welded or otherwise secured to collars 43, and the collars 43 are journaled on the shaft 40. It is therefore obvious from the disclosure that a simple means has been provided for vertically mounting the knife-coating guide The preferable construction of the knife-coating guide 4I is illustrated in Figures 3, 4, and 5. As the knife-coating guides on each side of the machine are similar but of opposite hands, like reference characters will indicate similar parts. A stationary ear 44 is secured to the knife-coating guide 4I by a suitable brace 45. Guides 46 are secured about the stationary ear 44. A movable disc 41 is journaled within the stationary ear 44 and has secured thereon a flange member 48 forming an annular groove 49 with the movable disc. The guides 46 extend into the annular groove 49 to prevent lateral movement of the disc 41; but, however, rotational movement of the disc is permitted. The movable discs 41 which are laterally spaced substantially the width of the sheet material or width of the unit to be knifecoated, serve to support a knife or blade 50 for knife-coating the sheet material. Additional transverse support is given to the blade or knife 50 by a channel shaped support 5I welded or otherwise secured to the knife 50. The channel 5I is also welded or otherwise secured to the laterally spaced discs 41 and extends therefrom as indicated in Figure 5. Stub shafts or shaft means 52 are adjustably secured to the U-shaped channel 5I. Referring to Figures 4 and 5, the stub shafts are adjustably secured to the channel shaped support 5I by set screws 5I' or other suitable means and form means, for adjusting the blade with respect to the shaft means. It is defined in the claims that the construction comprising the guides 46, the movable disc 41, ange 48 and annular groove 49 provide means adapted to engage the annular groove! and secured to the knife-coating guide whereby the knife is adapted for vertical adjustments through angular movement as the discs are rotated.

Referring to Figures 1 and 2, I will now describe a novel means for vertically adjusting the blade 50 so that the apparatus for knife-coating can be adjusted for different thicknesses of sheet material or thicknesses of the thermal units to be knife-coated. As the means for providing for. the vertical adjustment of the blades 50 to accommodate for the various thicknesses of material to be knife-coated is the same on both sides of the machine, like reference characters will indicate similar parts. Supports 53 are laterally positioned on the supporting frame l I. .TIhe supports 53 by suitable tongue and groove or other means provide for vertical adjustment of bearings 54 in which are journaled the stub shafts 52. A hand wheel 55 secured to an adjusting screw 56 at its upper end serves to provide for vertical adjustment of the bearing 54 as the adjusting screw 58 is in threaded engagement with the bearing 54.

Referring now to Figures 1 to 6 inclusive, I will now describe the novel means that I have provided for vertically. adjusting the blade' 50 whereby the knife-coating apparatus is adjusted for different thicknesses of sheet material to.

gether with means for adjusting the blade 50 with respect to the sheet material wher'eby the thickness of the coating applied by my novel knife-coating apparatus is varied. AV preferred embodiment of an adjusting mechanism 51 for .adjusting the thickness of the coating to the sheet of material, as best illustrated in Figures 1, 2 and 6, comprises a worm- 58 secured to a shaft 59. The shaft and worm 58 and 59, respectively, are journaled in brackets 50 formed preferably on the right hand vertically adjustable bearing 54. A worm wheel 5I secured to the right-hand stub shaft 52 is also in engagement with the worm 58. It is evident that as a hand wheel 62 which is secured to the shaft 59 is rotated that the worm 58 and worm wheel 6I are also in turn rotated. As the worm wheel 6l is rotated, it is evident that the knife or blade 50 is vertically adjusted. Since the discs 41 are journaled in the stationary ears 44, rotation of the worm wheel 8l will therefore cause rotation of the discs 41 which support the knife or blade 50. It is obvious from the foregoing disclosure that a novel means has been provided for the vertical adjustment of the knife-coating blade 50 with respect to the sheet material whereby the thickness of the coating applied to the sheet material can be varied as the sheet material is conveyed through the knife-coating apparatus. Furthermore, it is also evident that the knife-coating apparatus can be vertically adjusted to the different thicknesses of material to be knife-coated by this novel apparatus. y

In order that the sheet material and the thermal insulating units which I coat with my novel coating apparatus shall at all times be provided with a uniform coating, I provide a novel means for applying pressure to the sheet material whereby its surface is kept substantially level as it is conveyed through the means for knife-coating. In my preferred embodiment of the invention, the preferred means is preferably a plurality of rolls 63 suitably supported. Bearing supports 94 serve to support pressure rolls 83. The supports 94 extend laterally and downwardly over the knife-coating guides 4|. Horizontal bearing supports 65 secured to the lower ends of lithe supports 64 serve to journal the shafts of the pressure rolls 63. The length of the pressure rolls together with the bearings is such that they are mounted within the knife-coating .guides 4I.

As best indicated in Figure 2, pressure springs 66 provide spring pressure for maintaining the pressure rolls 63 in contact with the upper surface of the sheet material or thermal insulating units which are to be knife-coated. From the foregoing description it is obvious that a novel means has been disclosed for applying pressure to the sheet material whereby the surface of the.

sheet material is kept substantially level as it is conveyed through the means for knife-coating.

Having thusdisclosed in detail the novel features of my invention, referring to Figures 1 and 2, I will now describe the preferred manner in which I choose to operate my novel apparatus. Since the insulating units or sheet material to be knife-coated is preferably fed by hand from the operators station I5, Figure 1, I'in the direction of the arrows, .as the operator feeds the sheet material over the rolls l1 to the brush II8, the sheet material is picked up by the conveying means l2. As the surface of the sheet material is being brushed, a shield 61 prevents any foreign matter from flying into the face of the operator.

The conveying means. l2 which comprises the front and rear feed rolls respectively of my preferred embodiment is operated at a speed suflicient to provide a good production from the knife-coating apparatus and also so that a uniform and thin coating may be applied to the surface of the sheet material. In order to operate the conveying means l2, sprockets 68 are preferably\positioned on the left handside of the lower feed rolls 28 and secured to their supporting shafts 30. Sprockets 69 are secured to the shaft of a motor 10 and serve to drive the feed rolls 28 in unison through chains 1I passing over the sprockets 58 and B9. It is obvious from the description that the feed rolls will feed the sheet material through and under the pressure means provided by the pressure rolls B3 to the knife-coating means I4 and from there the conveying means at the outlet of the knife-coating apparatus will then convey the sheet material which has been knife-coated to the operators station I6.

The bitustatic or bitumastic coating or other material which is knife-coated on the surface of the sheet material passing through my novel knife-coating apparatus is preferably prepared so that it has a consistency which can be considered a trowel consistency. By this I mean, the consistency of the material applied to the surface is such that it may be readily applied with a trowel, in the usual manner. The bitustatic or bitumastic coatings and the likereferred to above are preferably materials well known in the trade comprising preferably an asphaltic compound comprising asphalt, fillers and suitable solvents, the resulting compound'having `a flash point of not less than F, by the Cleveland Open Cup Method, and usually having a specic gravity 'of 1.260 for normal operating conditions. The coating after being applied is preferably dried during a period not less than 1 hour at a temperature of approximately F. The compound for knife-coating is preferably placed between the knife-coating blade 50 and the last pressure roll Il, with respect to the direction in which the sheet material is moving. It is obvious that a puddle of the compound Visformed between the knife-coating blade and the last pressure roll I3. The knife-coating guides 4| at the sides of the sheet material prevent the compound from coating the edges of the sheet material so that only the upper surface of the sheet material will be coated.

It is apparent to one skilled in the art that, from time to time, the angle of the knife-coating blade 5I has to be changed as well as the pressure of the knife or blade 50 on the fiber board or sheet material being coated. It is obvious from the previous disclosure of my apparatus that, by adjusting with the hand wheel 56,V the knife-- coating blade 50 can be moved up and down to accommodate for various thicknesses of sheet material'passing through the apparatus.: It is also obvious that, as the knife 50 is moved up or down or as the angle is changed, the guides 4|, go with it and engage the sides of the sheet being coated thereby preventing the coating material from running over the edges of the board or sheet. By rotating the hand wheel 62 in either direction, it is apparent that the thickness of the coating applied to the surface of the sheet material is readily adjusted. 'I'he adjustment, therefore, which can be made by the hand wheels and 62 serve from time to time to adjust the angle of the knife-coating blade 50 as well as the pressure on the surface of the sheet material being coated. From the description of the means for adjusting the {knife-coating blade 50, it is obvious that the adjustment can be made simultaneously as the sheet material is being conveyed through the knife-coating apparatus without having to stop the apparatus to make the necessary adjustments.

It is evident that I have disclosed a novel apparatus for knife-coating the` sheet material, wherein, the sheet material as it is conveyed through the apparatus is simultaneously cleaned and knife-coated. It is also evident that I have disclosed a novel conveying means together with .means for adjusting the knife-coating apparatus as the sheet material is conveyed. It is also within the scope of this invention that other suitable conveying means can be provided instead of the feed rolls disclosed in my preferred embodiment. An equivalent conveying construction, as set forth in the claims as means for conveying would be a suitable'belt conveyor, as well understood inthe art. It is also obvious that the compound for coating the surface of the sheet material may be applied as I have disclosed by pouring a batch of the compound in ahead of the knife-coating blade 50, or it may be applied by having it flow from a suitable container at a uniform rate ahead of the knife-coating blade Il, as it is well' understood in the art of coating. It is to be understood that, when individual units to be coated are fed through my machine, they are fed to form substantially a continuous sheet with the ends of adjacent units abutting each other. Units prepared and knife-coated as described may have a suitable sealer coat, as shellac, applied followed by a surface coat of a satisfactory type of pigmented deck paint or the like which may be baked firmly to the knife-coated surface and sealer coat of the units if it is required. The units with such a finish are preferably used for fioor surfaces, roof decks, or they are used without the sealer coat and surface coat as a base material in connection with the installation of flooring, 'Ihese units may be secured in place by laying in hot asphalt or with suitable adhesive materials.

While the above description of the novel knifecoating apparatus discloses a preferred embodiment of my invention, the detail constructions are not essential and may be varied without departure from the scope of the invention as defined in the following claims.

What is claimed is:

1. In an apparatus for knife-coating sheet materialhaving substantial thickness, the combination with means for conveying the sheet material, of means for knife-coating the sheet material, and guide means comprising laterally spaced and pivoted members for guiding the sheet material, said guide means adapted to engage the edges of the sheet material; whereby, as the sheet material is conveyed, only the surface of the sheet material adjacent the means for knife-coating is coated.

2. In an apparatus for knife-coating blanks of sheet material, the combination with means for knife-coating a blank, of means for applying pressure to a blank, means for conveying a blank to be coated to the means for knife-coating through the means for applying pressure, and means for conveying the blank from the means for knife-coating after the blank has a coating applied thereto.

3. In an apparatus for knife-coating a blank of felted fibrous sheet material, the combination with means for knife-coating the blank, of means for cleaning the blank, means for applying pressure to the blank, means for conveying the blank through the means for cleaning the blank and to the means for knife-coating, and means for conveying the blank from'the means for knifecoating; whereby, as the blank of fibrous sheet material is conveyed it is simultaneously cleaned and kept substantially level as it is knife-coated.

4. In an apparatus for knife-coating sheet material, the combination with means for knifecoating the sheet material, means for conveying the sheet material, of means for applying pressure to the sheet material whereby its surface is kept substantially level as it is conveyed through the means for knife-coating, and means for knife-coating the sheet material; whereby, the sheet material is uniformly coated as it is conveyed.

5. In an apparatus for knife-coating sheet material, the combination with means for conveying the sheet material, of means for knife-coating the sheet material comprising'a knife transversely mounted with respect to the direction in which the sheet material is conveyed, means for adjusting the knife with respect to the sheet material, whereby the thickness of the coating applied to the sheet material is varied so that a uniform coating is applied as the sheet material is conveyed, and means for applying pressure to the sheet material in advance of the means for knife-coating whereby the surface of the sheet material is kept substantially level as it is conveyed through the means for knife-coating.

6. In an apparatus for knife-coating sheet `material, the combination with means for conveying the sheet material, of means for knife-coating the sheet material comprising pivoted knifecoating guides and a revolvable blade transversely mounted with respect to the pivoted knife-coating guides and the direction in which the sheet material is conveyed, means for vertically adjusting the revolvable blade whereby the apparatus is'adjusted for different thicknesses of sheet material, and means for adjusting the revolvable blade with respect to the sheet material whereby the thickness of the coating applied to the sheet is varied;

'rfIn an apparatus for knife-coating'sheet material, the combination with means for conveying the sheet material, of means for knife-coating the sheet material comprising knife-coating guides and a blade transversely mounted with respect to the direction in which the sheet material is conveyed, means for vertically adjusting the blade whereby the apparatus is adjusted for different thicknesses of sheet material, and means for adjusting the blade with respect to the sheet material comprising means mounted on the last mentioned means in conjunction with means mounted on the knife-coating guides, whereby the thickness of the coating applied tothe sheet is varied.

8. In an apparatus for knife-coating sheet material, the combination of a blade transversely mounted with respect to the direction in which the sheet material is conveyed, knife-coating guides' adapted for angular movement and for supporting the blade, means for vertically adjusting the blade whereby the apparatus is adjusted for different thicknesses of sheet materiall and means for adjusting the blade with respect to the sheet material mounted on the last mentioned means, whereby the thickness ofthe coating applied to the sheet is varied as the sheet material is conveyed through the apparatus.

9. In an apparatus for knife-coating sheet material, the combination of vknife-coating guides pivotally mounted for vertical movement, a blade transversely mounted with respect to the knifecoating guides, means for adjustably mounting the blade on the knife-coating guides, means for vertically adjusting the blade whereby the apparatus is adjusted for different thicknesses of sheet material, and means for adjusting the blade with respect to the sheet material whereby the thickness of the coating applied to the sheet is varied,

10. In an apparatus for knife-coating sheet material, the combination of knife-coating guide means mounted for vertical movement, said guide means comprising vertically mounted side sheets adapted to engage the sheet material, a blade transversely mounted with respect to the side sheets, means for adjustably mounting the blade on the vertically mounted side sheets, means for vertically adjusting the blade whereby the apparatus is adjusted for 'different thicknesses of sheet material, and means mounted on the last mentioned means for adjusting the blade with respect to the sheet material. i

11. In an apparatus for knife-coating sheet material, the combination with knife-coating guides pivotally mounted for vertical movement,

of a bladetransversely mounted with respect to the knife-coating guides, means for rotatably mounting the blade on the knife-coating guides, means for vertically adjusting the blade, and means for rotatably adjusting the blade mounted onthe last mentioned means, whereby the thickness of the coating applied to the sheet is varied.

12. In an apparatus for knife-coating sheet material, the combination with knife-coating guides mounted for vertical movement, of a blade transversely mounted with respect to the knifecoating guides, means for supporting the blade comprising a transverse support and shaft means adapted for rotation, means for adjusting the blade with respect to the shaft means, means for vertically adjusting the blade adapted to mount vthe knife and adapted to rotate in the knifecoating guides, said discs formed with an annular groove, and means adapted to engage the annular grooves and secured to the lmife-coating guides whereby the knife is adapted for vertical adjustment as the discs are rotated.

14.- Apparatus for knife-coating sheet material comprising means for conveying the sheet material through the apparatus, means for cleaning the sheet material, means for applying pressure to the sheet material whereby its surface is kept substantially level as it is conveyed through the apparatus, means for knife-coating the sheet material comprising laterally spaced guides adapted toengage the edges of the sheet as it is conveyed through the apparatus, and means for angularly adjusting the means for knife-coating the sheet material; whereby, as the sheetmaterial is conveyed in an horizontal plane, the thickness of the coating applied to sheet material can be varied and the laterally spaced guides allow4 only the upper surface of the sheet material to be coated.

15. The combination with a knife-coating apparatus for sheet material, of means for brushing the sheet material, means for knife-coating the sheet material, means for applying pressure to the sheet material wherebyv its surface is kept substantially level as it is conveyed through the means for knife-coating, roller feed means for conveying the sheet material in an horizontal plane through the means for brushing the sheet material and means for applying pressure to the means for knife-coating the sheet material, means for adjusting the means for knife-coating the sheet material whereby the thickness of the coating applied to the sheet material is varied as the sheet is conveyed in an horizontal planeA through the knife-coating apparatus, and means for conveying the sheet material from the means for knife-coating the sheet material.

16. The combination with a knife-coating apparatus for blanks of felted fibrous sheet material, of means for brushing a blank, means for knife-coating the blank comprising a transversely extending knife, roller feed means for conveyfeed means, and means for conveying the blank from the means for knife-coating the blank.

17. Apparatus for knife-coating sheet material comprising vertically movable and ltransversely positioned knife-coating guides adapted to engage the edges of the sheet material, a knife transversely mounted with respect to the knifecoating guides, means for adjustably mounting the knifeon the knife-coating guides, means for vertically adjusting the blade and knife-coating guides whereby the knife-coating apparatus is adapted for different thicknesses of material, and means for adjusting the Vknife whereby the thickness of the coating applied to the sheet. material is varied.

18. In an apparatus for uniformly knife coating a blank of felted fibrous sheet material, the combination with means for conveying the blank of felted fibrous sheet material, of means for knife coating the blank of felted fibrous sheet material whereby the sheet material is uniformly coated as it is conveyed, means for adjusting the thickness of the knife coating on the blank of felted fibrous sheet material, and means for applying pressure to the blank whereby its surface is kept substantially level as it is uniformly knife coated.

19. In an apparatus for uniformly knife coating a thermal insulating unit, the combination with means for conveying the aforesaid unit, of means for knife coating the unit whereby the unit is uniformly coated as it is conveyed, guide means comprising laterally spaced members for guiding the unit and adapted to engage the edges of the unit whereby the coating is applied only to the surface of the unit. and means for applying pressure to the unit whereby its surface is kept substantially level as it is uniformly knife coated.

' FLOYD W. ADAMS. 

